External combustion engine and method of converting internal combustion engine thereto

ABSTRACT

A hydrogen fuel zero or low emissions external combustion engine and a method to convert an internal combustion engine thereto. The invention includes devices, modifications, alterations, kits and methods for converting an internal combustion (IC) engine or engine design to the external combustion engine while using many of the components of the internal combustion engine. The external combustion engine includes a hydrogen tank to supply hydrogen fuel, a hydrogen flash vaporizer (HFV) to combust the hydrogen fuel and vaporize an atomized liquid introduced into the hydrogen flash vaporizer into an expanding fluid vapor (EFV), and an engine to receive the expanding fluid vapor and convert an expansion force thereof into mechanical force with a superior level of efficiency derived from a unique heat scavenging and cylinder shrouding design.

COPYRIGHT NOTIFICATION

This application includes material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent disclosure, as it appears in the Patent and Trademark Office files or records, but otherwise reserves all copyright rights whatsoever.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an external combustion engine, and more particularly, to a hydrogen fueled external combustion engine and a method to convert an internal combustion engine thereto, with application of this invention being for engines used in transportation, whether on land, water, or in the air. A secondary use may be in stationary engines.

2. Description of the Related Art

Global carbon based fuel consumption in vehicles to move people, as well as deliver goods and services, has created significant air and water quality problems throughout the world, and in particular in industrialized countries. A variety of alternate energy sources intended to replace use of carbon based fuel in powering vehicular transportation have been proposed or developed, however drawbacks to each have limited their viability or implementation on a global scale.

The zero emission design (ZED) engine disclosed herein is designed to combust hydrogen as a fuel. Hydrogen, the most plentiful element in the universe, and first on the periodic table, can be produced cost effectively by numerous means, but primarily through the electrolysis of water, the most plentiful substance on earth. Gasoline fueled internal combustion (IC) engines are generally 23% efficient in converting potential energy to mechanical force. Hydrogen fuel cell engines are generally 47% efficient in the transference of potential energy. External combustion of hydrogen is comparable to hydrogen fuel cell efficiency. When ignited, carbon-free hydrogen combines with oxygen in the air to produce environmentally benign water vapor, thereby eliminating carbon based fuel as a source of pollution. Hydrogen is the only fuel with no carbon which, at an octane rating of 130, can match the power of gasoline or diesel, such that hydrogen fueled vehicles are currently feasible. Recognizing the benefits of hydrogen fuel, governments and corporations have signed agreements beginning in 2006 to develop hydrogen fueling stations in the European Union and in North America.

However, the current multi-trillion dollar global investment in existing internal combustion engines and related chassis designs is a key consideration in regard to the implementation of alternate engine designs or a major change in the current transportation paradigm. The global re-engineering of all powertrain and chassis designs for a uniquely different engine would be a lengthy, costly, and arduous task with a high probability of failure, whereas utilization of the existing manufacturing infrastructure is likely to foster reduced production costs and accelerate adaptation of new technology.

Accordingly, the present invention discloses a hydrogen fueled external combustion engine and a technically efficient method of re-engineering existing internal combustion vehicles or engine designs to zero or low emission vehicles, and in particular to vehicles fueled by an environmentally-friendly fuel, such as hydrogen. The technical aspects of the present invention disclosed herein provides an alternative to basic internal combustion engine powered transportation in developing and third world countries where the cost of implementation may be a major consideration.

SUMMARY OF THE INVENTION

The present invention discloses a hydrogen fueled zero or low emissions engine, and a method to convert an internal combustion engine thereto.

The present invention also provides a hydrogen fueled zero or low emissions engine that can be manufactured using current chassis design and internal combustion engine components, thereby utilizing foundry, machining, and assembly processes currently in use globally to facilitate quick and economical conversion to hydrogen fueled zero or low emissions engine powertrain productions.

The present invention also provides a method of using existing internal combustion engine components to retrofit existing carbon fueled vehicles to hydrogen fueled zero or low emissions ZED engine powertrains.

The present invention also provides devices, modifications, alterations, kits, and methods to convert an engine from internal combustion carbon based fuel to external combustion hydrogen fuel.

The present invention also provides a hydrogen fueled zero or low emissions engine capable of providing maximum power at a lower rotating speed, minimal contamination of lubricant, and an increase in engine life with an lower overall operating cost than what may be achieved with a carbon fuel based internal combustion engine design. The hydrogen fueled zero or low emissions engine of the present invention has significantly fewer components than a conventional internal combustion engine, which reduces production cost, decreases the probability of component failure, and reduces maintenance.

Additional aspects and advantages of the present invention will become apparent in light of the present specification, including claims and drawings, or may be learned by practice of the invention as disclosed herein.

The foregoing and/or other aspects and utilities of the present invention may be achieved by providing an external combustion engine, including a hydrogen tank storing a source of hydrogen fuel, a hydrogen flash vaporizer (HFV) to combust the hydrogen fuel and vaporize an atomized liquid introduced into the hydrogen flash vaporizer so as to form an expanding fluid vapor (EFV), and an engine to receive the expanding fluid vapor and convert an expansion force thereof into mechanical movement.

The external combustion engine of the present invention further includes a plurality of actuated vapor devices to regulate the introduction of the expanding fluid vapor into the engine.

The engine of the present invention may be adapted from a conventional internal combustion engine design.

The external combustion engine of the present invention may further include an information processing and engine control system.

The information processing and control system regulates the flow of hydrogen to the hydrogen flash vaporizer, and the flow of expanding fluid vapor to the engine.

The external combustion engine further includes a hydrogen flash vaporizer exhaust system to direct heat produced by the combustion of hydrogen to the engine to heat the expanding fluid vapor introduced into the engine.

The engine may be adapted from a conventional internal combustion engine design and the hydrogen flash vaporizer exhaust system directs the to coolant passages defined in the conventional internal combustion engine.

The engine disclosed in the present invention may be adapted from a conventional internal combustion engine design and the hydrogen flash vaporizer exhaust system directs the heat to at least one of original coolant passages defined in the internal combustion engine and other passages within the engine block to shroud the operating pistons/cylinders therein with heat.

In one disclosed embodiment of the present invention a cylinder may incorporate at least one groove connected to the original coolant passages, and the cylinder may be fitted with a shrouding sleeve to define other passages for the heat to shroud the piston.

In the disclosed embodiment of the present invention the hydrogen tank includes a hydride tank and wherein heat is directed from the engine to the hydride tank to release the hydrogen fuel.

In one embodiment the hydrogen tank includes a hydride tank and wherein heat is directed from the coolant passages defined in the engine to the hydride tank to release the hydrogen fuel.

The hydrogen tank may include a hydride tank and wherein heat produced by the combustion of hydrogen in the hydrogen flash vaporizer is directed to the hydride tank to release the hydrogen fuel.

In the invention disclosed the hydrogen flash vaporizer includes a hydrogen flash vaporizer body defining a heating chamber, a combustion chamber, and an exhaust, a plurality of heating tubes disposed within the heating chamber to connect the combustion chamber to the exhaust, and a hydrogen burner, disposed in the combustion chamber to combust the hydrogen fuel and heat an inside surface of the heating tubes, wherein an air intake is provided in the combustion chamber to combine the hydrogen fuel with air during combustion thereof, and wherein the heated air travels through the heating tubes to the exhaust.

In the invention disclosed the atomized liquid comprises a high density fluid (HDF). The high density fluid may include a binary mixture of two fluids selected as having cooperative molecular weights so as to widen the temperature range at which the binary fluid converts to a vapor. In one embodiment the high density fluid includes a binary mixture of water and ammonia comprised of 5-50% ammonia and 50-95% water or 15-50% ammonia and 50-85% water.

The foregoing and/or other aspects and utilities of the present invention may also be achieved by providing an external combustion engine, including a high density fluid reservoir to store high density fluid, a hydrogen fuel tank to store hydrogen fuel, a hydrogen flash vaporizer to combust hydrogen fuel received from the hydrogen fuel tank and vaporize a high density fluid received from the high density fluid reservoir into an expanding fluid vapor, a piston engine to receive the expanding fluid vapor and convert an expansion force thereof into mechanical force, and an exhaust to direct heat produced by the hydrogen combustion to the piston engine to heat the expanding fluid vapor introduced into the engine.

The engine disclosed herein may be adapted from a conventional internal combustion piston engine, and wherein heat may be directed to original coolant passages defined in the internal combustion piston engine.

The engine disclosed herein may be adapted from a conventional internal combustion piston engine, and wherein heat may be directed to at least one of original coolant passages and other passages so formed in the conventional internal combustion piston engine as to shroud the engine pistons with heat.

The engine may include at least one piston within a cylinder, and the method may further include engraving the cylinder with at least one groove connected to the coolant passages, and fitting a shrouding sleeve in the cylinder to define other passages in the cylinder to shroud the piston with the excess heat.

The foregoing and/or other aspects and utilities of the present invention may also be achieved by providing a method of converting a conventional internal combustion engine to a hydrogen fuel internal combustion engine, including installing a high density fluid reservoir to store high density fluid, installing a hydrogen fuel tank to store hydrogen fuel, installing a hydrogen flash vaporizer to combust the hydrogen fuel received from the hydrogen fuel tank and vaporize a high density fluid received from the high density fluid reservoir into an expanding fluid vapor, and modifying the conventional internal combustion engine to receive the expanding fluid vapor and convert an expansion force of the expanding fluid vapor into mechanical force.

The method of the present invention further includes the step of modifying the coolant passages of the conventional internal combustion engine to receive heat produced by the hydrogen combustion to heat the conventional internal combustion engine and heat of the expanding fluid vapor.

The method further includes modifying at least one of the coolant passages and other passages formed in the conventional internal combustion engine to receive heat produced by the hydrogen combustion to shroud the engine pistons with the heat.

The method further includes directing the heat from the cooling passages to the hydrogen tank to heat a hydride store therein and release the hydrogen fuel.

The high density fluid may comprise a binary mixture of water and ammonia.

The hydrogen fuel tank may include a hydride tank, and the method may further include directing heat produced by the hydrogen combustion to the hydrogen tank to release the hydrogen fuel.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects and advantages of the present invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 illustrates a piston cylinder of a conventional piston internal combustion engine.

FIG. 2 illustrates a piston cylinder of a ZED engine according to an embodiment of the present invention.

FIG. 3 illustrates a ZED engine according to an embodiment of the present invention.

FIG. 4 illustrates a hydrogen flash vaporizer according to an embodiment of the present invention.

FIG. 5 illustrates a heat director according to an embodiment of the present invention.

FIGS. 6A-6B illustrate a ZED engine according to an embodiment of the present invention.

FIGS. 7A-7B illustrate a ZED engine according to another embodiment of the present invention.

FIGS. 8A-8B illustrate a ZED engine according to another embodiment of the present invention.

FIG. 9 illustrates an actuated vapor injector (AVI) according to an embodiment of the present invention.

FIG. 10 illustrates cylinder twinning according to an embodiment of the present invention.

FIG. 11 illustrates a vaporizer exhaust bypass according to an embodiment of the present invention.

FIG. 12 illustrates a shrouding cylinder sleeve according to an embodiment of the present invention.

FIG. 13 is a diagram illustrating an interconnection of an engine control unit to various components of the engine according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures.

As used herein, the words “a” or “an” may mean one or more of an item. As used herein, “operationally coupled” means that there is a functional interaction between one or more components. For example, an engine control unit (ECU) may be operationally coupled to one or more actuated vapor injector (AVI), and by controlling a duration of actuated vapor injector opening, a power of an engine may be controlled by a volume of expanding fluid vapor introduced into a cylinder. Similarly, a sensor installed in an expanding fluid vapor condenser may determine that expanding fluid vapor is insufficiently cooled to return to a liquid state, as high density fluid, and so, may actuate a cooling fan to form a condensate. Multiple functions such as these may be controlled by the engine control unit, and may be included within the definition of operationally coupled.

Terms that are not otherwise defined herein are used in accordance with their plain and ordinary meaning in the English language or according to their use in trade. In the following detailed descriptions, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to one of ordinary skill in the art that these specific details need not be all used to practice the present invention. In other circumstances, well-known structures, compounds, circuits, processes, interfaces, components, and methods have not been shown or described in detail in order not to unnecessarily obscure the present invention.

The present invention is directed to a hydrogen fuel zero or low emission engine design (ZED) engine and a method to convert an internal combustion (IC) engine thereto. A conventional piston driven internal combustion engine can serve as a base for the ZED engine. While the embodiments described herein are directed to an IC piston engine, the present invention is not limited thereto. Instead, the present invention is adaptable to other variants of IC engines, including rotary, turbine and others in the art whereby a carbon based fuel is burned internally to produce mechanical power. For example, a ZED engine can be fabricated using commercially available internal combustion engine components, or an existing internal combustion engine vehicle manufacturing process can be modified to incorporate the ZED engine into an existing chassis or vehicle design in place of the conventional internal combustion engine. In addition, the present invention can also be embodied as a method to re-power existing vehicles by replacing an existing internal combustion engine with the ZED engine. Such conventional internal combustion engines include, but are not limited to, those fueled by carbon based fuels such as gasoline, diesel, kerosene, or gaseous fuels without limitation as to displacement or physical size, mobile or stationary, use on land, sea or air, and without restriction in design, including piston, rotary, radial, turbine or other engine designs known in the art wherein a carbon based fuel is burned internally to produce mechanical power. In combustion engines, expanding gas is converted to mechanical motion, and thereby to movement of a vehicle. Gas expansion may be created by either combustion or by heating of the gas.

A common form of internal combustion engine is the four-stroke piston engine. As illustrated in FIG. 1, a four-stroke piston engine is characterized by four strokes, or reciprocating movements of a piston [31] within a cylinder [30] to impart mechanical movement of a crankshaft [8]. A four stroke cycle begins when the piston [31] is farthest away from the axis of a crankshaft [8], i.e. at its highest position within the cylinder [30]. On an intake or induction stroke, the piston [31] descends from the top of the cylinder [30], reducing a pressure inside the cylinder [30]. A mixture of fuel and air is drawn by the pressure reduction into the cylinder [30] through an inlet valve [3] port. The intake valve [3] then closes, and a compression stroke of the piston [31] ascending within the cylinder [30] compresses the fuel-air mixture. The air-fuel mixture is then ignited near the end of the compression stroke, usually by a spark plug [34] (for a gasoline or Otto cycle engine) or by the heat and pressure of compression (for a Diesel engine). The resulting pressure of burning gases pushes the piston [31] through the power stroke downward within the cylinder. In the exhaust stroke, the piston [31] ascends within the cylinder [30] to push the products of combustion from the cylinder through an exhaust valve [4]. The opening and closing of valves [3] and [4] (biased by springs [26]) are controlled by a conventional camshaft, not shown.

As illustrated in FIGS. 2 and 3, a conventional internal combustion piston engine design can be used as a base for the ZED engine of the present invention. The ZED engine disclosed herein operates according to a two stage process whereby a high density fluid is heated through combustion of hydrogen in a hydrogen flash vaporizer to produce an expanding fluid vapor. The expanding fluid vapor is then directed or metered into a piston cylinder [30] through an intake valve [3], wherein mechanical motion is induced by movement of a piston [31] within said cylinder [30] from the pressure of the expanding fluid vapor.

The high density fluid is selected to optimize its conversion from a fluid to a vapor. For example, the high density fluid may comprise a binary fluid of components having adjacent molecular weights in order to widen a temperature range for fluid conversion to vapor, in that fluids of similar molecular weight maintain a better continuity in the range of vaporization between the fluids combined in the high density fluid.

In one embodiment of the present invention the high density fluid includes a binary mixture of ammonia and water. The molecular weight of ammonia is 17.0306 g/mol, and the molecular weight of water is 18.0153 g/mol. The water may be desalinated or distilled. The binary mixture may comprise about 5-50% ammonia and about 50-95% water, preferably about 10-50% ammonia and about 50-90% water. However, the present invention is not limited thereto, and the ratio between the binary components may vary from the percentages cited. For example, the percentage of ammonia in the high density fluid may vary according to a displacement size of the ZED engine and performance applications. Ammonia may be selected as one binary fluid because ammonia is readily available at low cost, and has a low vaporization point. However, while the high density fluid described above includes a binary mixture of ammonia and water, the present invention is not limited thereto. The high density fluid may include the use of other binary fluids combined to have a wider range of vaporization temperature than a single fluid.

However, the high density fluid may comprise a single liquid. An important characteristic of the high density fluid is an ability to minimize the effect of any variance in vaporizer temperature where vapor will continue to be produced and will not substantially affect a performance of the vehicle.

General Operation of the ZED Engine

An exemplary operating cycle for a ZED engine is described below with respect to an embodiment of the ZED engine illustrated in FIG. 3.

In the embodiment illustrated, a conventional piston driven internal combustion engine [1] serves as the foundation for the ZED engine. The components of the ZED engine can be adapted from a conventional IC engine, including, but not limited to, the engine block [1], the crankshaft [8], connecting rods [9], and pistons [31].

Hydrogen fuel is supplied by hydrogen fuel tank [100]. The devices used to introduce hydrogen fuel to the hydrogen fuel tank [100] may be of any so designed in the art of the craft. The hydrogen fuel tank [100] stores the hydrogen gas and/or hydrogen supply and supplies it to the ZED engine. The supply of fuel may be regulated mechanically and/or electronically by an operationally coupled engine control unit (ECU) (not illustrated). For example, the fuel supply can be regulated by a fuel volume regulator [18] as illustrated in FIG. 4.

Hydrogen from the hydrogen fuel tank [100] is carried to the hydrogen flash vaporizer [10] by fuel line [17] where it is ignited. The hydrogen flash vaporizer [10] includes a hydrogen burner [12] positioned and designed in such a manner that the heat conveyed from burner [12] increases the temperature of the high density fluid to a level so as to form the expanding fluid vapor.

The expanding fluid vapor formed in the hydrogen flash vaporizer is conveyed to the engine cylinder(s) [30] inside the engine block [1] via the expanding fluid vapor outlet [20]. If the ZED engine includes actuated vapor injectors, the actuated vapor injectors are mechanically or electrically actuated to convey the expanding fluid vapor to the engine cylinder(s) [30] to create mechanical motion in the ZED engine. The actuated vapor injectors may be controlled and/or operationally coupled in a manner that will affect engine rotational speed, engine power output, and engine rotational direction.

The introduction of expanding fluid vapor into the ZED engine imparts mechanical movement in the piston(s) [31], and said movement may be conveyed by mechanical motion of a vehicle or device thereby attached to perform a function as determined by the operator.

The high density fluid is introduced as an atomized liquid into a high density fluid heating chamber [11 a] in the hydrogen flash vaporizer [10]. When the atomized fluid contacts superheated internal surfaces forming the high density fluid heating chamber [11 a] as further described below in connection with FIG. 4, the atomized liquid is immediately vaporized, thereby expanding in volume, for example, in the range of approximately 2000:1. The resultant expanding fluid vapor is then be held under pressure in an intake manifold [2] and/or in the hydrogen flash vaporizer [10]. Alternatively, the hydrogen flash vaporizer [10] and the components leading to the intake valve [3] or cylinder [30] actuated vapor injector may be pressurized. This maximizes an available volume of pressurized expanding fluid vapor available to the ZED engine so that the expanding fluid vapor pressure is not rapidly drawn down when the rotational speed of the ZED engine is increased rapidly. The intake manifold [2] or the hydrogen flash vaporizer [10] may be electronically or mechanically actuated and/or operationally coupled to the engine control unit to direct and meter expanding fluid vapor to the ZED engine when the rotation of the engine is mechanically determined to cause mechanical motion by movement of the piston [31], or similar engine components.

The expanding fluid vapor is then discharged from the engine block [1] through an exhaust manifold [40] and collected in a condenser [50] which condenser cools the expanding fluid vapor to a condensation temperature and condenses the expanding fluid vapor back into liquid high density fluid. The high density fluid is then collected in a reservoir [60], whereupon it is pumped by a high density fluid pump [51] under pressure to a high density fluid regulator [15] to be reintroduced into the hydrogen flash vaporizer [10] for reuse as a high density fluid in a closed circuit manner.

Expanding fluid vapor operating pressure can be maintained under varying load and operating conditions according to the volume of high density fluid introduced into the hydrogen flash vaporizer [10] and/or the volume of hydrogen or other fuel introduced into the hydrogen flash vaporizer burner [12]. For example, a high pressure could be attained by introducing a high volume of fuel and a high volume of high density fluid into the hydrogen flash vaporizer [10], while a low pressure could be maintained by minimizing the amount of fuel and minimizing the volume of high density fluid introduced into the hydrogen flash vaporizer [10]. Control of the ZED engine in the intermediate operating cycles may be performed by monitoring the expanding fluid vapor pressure in the manifold [2] or the hydrogen flash vaporizer [10] prior to release of expanding fluid vapor into the engine block [1], and maintaining said pressure. A startup cycle of the ZED engine is optimized through the rapid heating of the hydrogen flash vaporizer [10] and the conversion of low volume atomized high density fluid into high volume expanding fluid vapor.

External combustion of hydrogen can maximize a combustion efficiency of the engine and deliver operating characteristics consistent with extended engine life, greater horsepower and torque at lower RPM, and may also eliminate complex combustion control and emission devices associated with carbon based engine fuels.

In particular, the efficiency of the ZED engine can be enhanced by maintaining an optimal stoichiometric ratio of air to hydrogen through a wide range of operating conditions. By comparison, an internal combustion engine may intake the same amount of combustion air in a cylinder, regardless of operating conditions or fuel volume, thereby operating inefficiently outside the internal combustion engine stoichiometric ratio. With a virtually unlimited supply of combustion air, the ZED engine can operate within the ideal stoichiometric ratio of hydrogen combustion under all load conditions. In addition, because the pressure on an engine piston can be controlled, maximum pressure can be made against the piston at low revolutions per minute (typically 500 RPM) thereby reducing engine wear and increasing longevity of the ZED engine compared to an internal combustion engine which may maximize power at 5,000-6,000 RPM. This low RPM, high power characteristic, also manifests itself as a quicker throttle response time than an internal combustion engine. ZED engine external combustion of the hydrogen, or other fuel, also isolates non-combusted fuel from the cylinder, unlike an internal combustion engine where non-combusted fuel moves past the piston rings to contaminate the lubricating oil, an inherent deficiency of the internal combustion engine, especially with gasoline or diesel fuel which dissolve the lubricating oil, and thus, increases engine wear and potential engine failure. The ZED engine also has no combustion air contaminants entering the cylinder, unlike an internal combustion engine which must filter the air of contaminants so as not to damage the cylinders or contaminate the lubricating oil, both problems which are avoided by the ZED engine. When fueled by hydrogen combusted in the ZED engine, the hydrogen forms with oxygen in the air to create a zero-carbon exhaust. The use of hydrogen fuel can eliminate most if not all of the anti-pollution emissions devices associated with carbon based gasoline or diesel internal combustion engines whereby carbon derived pollutants must be reduced due to the inherent chemical composition of a carbon based fuel. The result is an improved performance in the ZED engine, and reduced manufacturing cost due to the elimination of internal combustion engine combustion and emission control devices. Notably, in an internal combustion engine the heat of combustion, which represents energy, is wasted through venting to the atmosphere through the engine exhaust, or dissipated to the atmosphere through the engine cooling system. In contrast, the ZED engine scavenges an excess combustion heat for conversion into mechanical use. Therefore, although the ZED engine may be based on an internal combustion engine design, the configuration of the ZED engine, uniquely combined with the particular ignition characteristics of hydrogen fuel, provides superior performance from the same basic design than a petroleum fueled internal combustion engine configuration.

As described above with respect to FIGS. 2-3, components of the ZED engine can be adapted from a conventional internal combustion engine, including, but not limited to, the engine block [1], the crankshaft [8], connecting rods [9], and pistons [31].

In a vehicle currently using an internal combustion engine, a conversion to a ZED engine, according to an embodiment of the present invention, may include: removal of the conventional fuel tank and fuel lines in the internal combustion engine; removal of unused internal combustion engine components, such as attached control devices, sensors, ignition system, electronics, fuel supply, cooling system, and selected exhaust components; installation of the hydrogen fuel tank [10] and installation of ZED engine fuel lines [17]; installation of the hydrogen flash vaporizer [10] and related components, such as, hydrogen flash vaporizer venting, throttle controls, monitoring gauges as applicable; installation of an expanding fluid vapor recovery system as applicable, including a high density fluid condenser [50], a high density fluid reservoir [60], and a high density fluid pump [51]; and installation of an engine control unit, if used, with related sensors and other components.

ZED Engine and System Components

Hydrogen fuel tank [100] may include any container suitable to store and/or supply hydrogen to the ZED engine as known within the art of such technology. The hydrogen fuel tank [100] may have a sensor(s) installed so as to determine and make known the amount of available hydrogen fuel therein. The hydrogen fuel tank [100] may have a valve(s) of such electrical or mechanical design so as to be filled and refilled and/or to shut-off or turn-on the supply of hydrogen to the hydrogen flash vaporizer. The hydrogen fuel tank [100] may be of such design as to safely avoid physical damage, corrosion, or other compromise of its structural integrity. The hydrogen fuel tank [100] may be controlled by or otherwise operationally coupled to the engine control unit. The hydrogen fuel tank [100] may be a tank for storing compressed hydrogen, liquefied hydrogen, metal hydride, borohydride, alanate, or any other hydrogen source and storage container as known in the art.

Three common ways to store hydrogen fuel in a tank is as a compressed gas at 5,000 psi, liquefied at −400° F., or in a hydride. For safety, cost, ease of manufacturing, and increased volume of storage, hydride storage tanks are beginning to dominate the industry. In these hydride tanks, hydrogen is combined with different metals to form inert molecules. To release the hydrogen, the hydride must be heated. This is a problem for hydrogen fuel cells as their exhaust is low-grade heat and cannot activate the hydrogen release. Similarly, internal combustion of hydrogen at 550° C. is too hot to release in the hydride tank in a controlled manner. In one embodiment of the present invention, a high-grade exhaust of the ZED engine, which may be at 100-125° C., is routed through a hydride tank [100] to release hydrogen for fuel and combustion. This is a highly efficient use of the hydrogen combustion heat, as other conventional hydrogen engines are limited to generating heat separately to release hydrogen from a hydride tank during engine operation.

To heat the hydride tank [100] to release the hydrogen, the exhaust [10 a] from the hydrogen flash vaporizer [10] can be routed by an exhaust pipe [110] to one end of the hydride tank [100]. The exhaust pipe [110] may penetrate the hydride tank [100] and divided into a plurality of smaller pipes routed at equidistant spacing throughout the length of the hydride tank [100]. The smaller pipes may then be collected at the opposing end of the hydride tank [100], connected to another pipe which also penetrates the hydride tank [100], and thereafter exhausted to the atmosphere through a discharge pipe [120]. The dissipation of the heat throughout the hydride tank [100] at a minimum of 100° C. is sufficient to heat the hydride stored therein and cause release of the hydrogen fuel during engine operation. The hydride tank [100] may be fixed in the ZED engine and refilled with hydrogen once depleted of hydrogen. A system to initiate hydrogen release, such as a start-up heater, may be included to release hydrogen from the hydride tank [100] prior to full engine operation.

An example of a hydrogen flash vaporizer according to an embodiment of the present invention is illustrated in FIG. 4. The hydrogen flash vaporizer allows rapid generation of expanding fluid vapor in the ZED engine, and thus, improves the rapid availability of power to the ZED engine. A flash vaporizer does not operate like a conventional boiler which introduces a liquid into a vessel, heats it slowly until it boils, and only then creates an expanding vapor. Instead, the liquid is sprayed, for example by atomization, into the hydrogen flash vaporizer where upon contact with superheated (about 550° C.) surfaces it instantly vaporizes and expands significantly to expanding fluid vapor (For example, by about 2000:1 by volume). The hydrogen flash vaporizer is highly efficient because the mass of liquid to be heated is minimal, and a superheated surface area of the vaporizer greatly exceeds the contact area of the liquid as compared to a boiler.

The hydrogen flash vaporizer may be of such material, design and function as to ignite hydrogen fuel and vaporize the high density fluid so as to form expanding fluid vapor. For example, the hydrogen flash vaporizer may be fabricated from stainless steel. FIG. 4 illustrates a hydrogen flash vaporizer [10] according to an exemplary embodiment of the present invention. As illustrated in FIG. 4, the hydrogen flash vaporizer [10] is connected by a fuel line [17] to facilitate the movement of hydrogen from the hydrogen fuel tank [100] to the hydrogen flash vaporizer [10]. The hydrogen flash vaporizer [10] as illustrated includes a hydrogen flash vaporizer body [11], a hydrogen burner [12], and a plurality of heating tubes [13]. The hydrogen flash vaporizer body [11] defines high density fluid heating chamber [11 a], a combustion chamber [11 b], and an exhaust [11 c]. The heating tubes [13] may be hollow and may be disposed within the heating chamber [11 a] to connect the combustion chamber [11 b] to the exhaust [11 c]. The hydrogen burner [12] is disposed in the combustion chamber [11 b] to combust the hydrogen fuel and heat an inside surface of the heating tubes [13]. An air intake [11 d] is provided in the combustion chamber [11 b] to combine air with the hydrogen fuel during a combustion thereof. Ambient air provides combustion air and ensures a complete combustion of the hydrogen, thereby efficiently extracting, by maintaining the optimal stoichiometric ratio of combustion throughout all load and fuel volume variations, a greater amount of energy from the combustion of the hydrogen than if air supply was restricted. The heated air from combustion travels through the heating tubes [13] to the exhaust [11 c]. The cross-sectional area of the exhaust [11 c] may be dimensioned to equal or exceed a combined cross-sectional area of the heating tubes [13] to prevent a constriction of the heated air flow. The hydrogen flash vaporizer [10] is shown including a fuel igniter [16] to initiate the combustion of hydrogen fuel. The hydrogen flash vaporizer [10] includes a fuel-off and fuel-on function, such as a shut-off valve [19], as well as variable fuel volume regulator [18]. The hydrogen flash vaporizer [10] may have a regulator [15] to regulate the introduction of high density fluid in a volume suitable for engine operation, as well as sensor(s) [15 a-15 b] to determine the volume of high density fluid in the hydrogen flash vaporizer, a sensor to monitor the volume of expanding fluid vapor to the actuated vapor injector(s), and a safety sensor(s) to monitor the hydrogen flash vaporizer [10] functionality. The high density fluid is introduced into the hydrogen flash vaporizer [10] as, for example, a stream of liquid splashed among the heating tubes [13] or by atomizer through the regulator [15] to contact the heating tubes [13] as an atomized fluid. Because the heating tubes [13] are tapered at a bottom portion thereof, any high density fluid which does not immediately vaporize may be collected inside of the heating chamber [11 b] in an area between the heating tubes [13] at a v-shaped collection point [11 e]. The collection point [11 e] may be disposed closest to the burner [12], and therefore may be the hottest point of the hydrogen flash vaporizer [10] capable of vaporizing the collected high density fluid in the least amount of time. In one embodiment of the present invention, the high density fluid is introduced into the heating chamber [11 b] as an atomized liquid. Upon contact with the heated heating tubes [13], the high density fluid vaporizes and expands to form expanding fluid vapor. The hydrogen flash vaporizer body [11] includes an expanding fluid vapor outlet [20] to supply expanding fluid vapor to the pistons [31] in the engine block [1]. The hydrogen flash vaporizer [10] as disclosed has provision for high density fluid condensate to be re-introduced to the ZED engine in a closed-loop operation. Alternatively the high density fluid may be introduced to the engine and not recovered by a condenser [50]. As illustrated in FIG. 4, a bottom portion of the heating tubes [13] may be tapered to increase a surface contact area of the combusting hydrogen fuel and define the collections points [11 e] to accelerate the vaporization of collected high density fluid.

The expanding fluid vapor generated in the hydrogen flash vaporizer [10] is conveyed to the engine cylinders [30] or actuated vapor injector(s) through the expanding fluid vapor outlet [20]. The expanding fluid vapor outlet [20] may be a tube of such volume, shape, design, insulation and material so as to contain the expanding fluid vapor in a state which may be consistent with the expanding fluid vapor produced in the hydrogen flash vaporizer [10]. For example, the expanding fluid vapor outlet [20] may be a stainless steel tube. Said tube may be of such design so as to incorporate a manifold to facilitate the flow of expanding fluid vapor to multiple actuated vapor injector locations or cylinders in particular embodiments. Heat loss in said tube may be mitigated by the use of insulation or short tubing.

As described, the expanding fluid vapor may be introduced to the engine cylinders [30] through the use of an actuated vapor injector(s) which may be either electrically or mechanically controlled.

The hydrogen flash vaporizer [10] may also regulate an introduction of high density fluid into the hydrogen flash vaporizer [10] to control mechanical operation of the ZED engine. An exhaust [11 c] of the hydrogen flash vaporizer [10] is shown positioned to exhaust toward engine block [1] to facilitate the heat shrouding of the engine block cylinders [30]. As illustrated in FIG. 5, in order to regulate a temperature of the combusted hydrogen exhaust, the hydrogen flash vaporizer [10] is shown including an ambient air bleed valve [35] so as to direct cooler ambient air into the combustion exhaust, to blend with, and cool the combustion exhaust prior to entering the engine block [1] to prevent overheating.

The ambient air bleed valve [35] comprises a valve [36] and a temperature sensor [37] operationally coupled to the valve [36]. The valve [36] may be electronically or mechanically activated to control the temperature of the exhaust heat introduced into the engine block [1] so as to be within the metallurgy limitations of the engine block [1]. The temperature sensor [37] may monitor a temperature of the engine block [1] and may directly activate the valve [36]. Alternatively, sensor [37] may be operationally coupled to an engine control unit of the ZED engine, wherein the engine control unit controls valve [36].

While for purposes of efficiency and heat-shrouding, the hydrogen flash vaporizer [10] preferably uses hydrogen as a fuel, the present invention is not limited thereto. Instead, the hydrogen flash vaporizer [10] may operate with other fuels. For example, conventional carbon based fuels may be used to generate the expanding fluid vapor. Gaseous carbon fuels, such as compressed natural gas, propane, or methane can be burned if routed through the hydrogen burner [12]. Liquid fuels, such as gasoline, diesel, JP-8, or alcohol, may require use of a vaporizer nozzle (not illustrated) adjacent to the hydrogen burner [12] to vaporize the liquid fuel prior to combustion. However, because conventional carbon-based fuels have a high radiant heat factor, the ZED engine may be modified to prevent the exhaust heat of a carbon fuel based combustion from warping and/or damaging the engine block [1].

For example, as illustrated in FIG. 11, the ZED engine may include a vaporizer exhaust bypass [400]. The vaporizer exhaust bypass [400] may include a bypass valve [401] and a discharge exhaust [402]. The bypass valve [401] may be disposed in expanding fluid vapor outlet [20] and may be electronically or mechanically activated to direct a vaporizer exhaust away from the engine block [1] and into the discharge exhaust [402]. As illustrated in FIG. 11, the bypass valve [401] may include a diverter plate to selectively allow passage of the vaporizer exhaust into the engine block [1] or to block passage of the vaporizer exhaust into the engine block [1] and instead direct the vaporizer exhaust into the discharge exhaust [402]. The discharge exhaust [402] may exhaust the vaporizer exhaust directly to the atmosphere. Alternatively, the ZED engine may include conventional internal combustion engine exhaust components connected to the discharge exhaust [402] to reduce the emissions of a carbon based fuel exhaust. The addition of the vaporizer exhaust bypass [400] gives the ZED engine a dual fuel capability, where the vaporizer exhaust heat can be used to thermally shroud the engine block cylinders [30] when hydrogen is used, and where the vaporizer exhaust heat can be safely diverted from the engine block [1] when carbon based fuels are used to prevent warping or damage to the engine block [1]. Accordingly, the ZED engine may be embodied as a multi-fuel engine, providing additional versatility to the engine, especially for remote or military applications where hydrogen fuel may not be available.

The high density fluid reservoir [60] may be such volume, shape, and design that it provides for the operation of the engine in either the vented or condensate application as intended. Said high density fluid reservoir [60] may be equipped with a sensor to measure the volume content of high density fluid within the high density fluid reservoir [60], a one-way valve which may be installed either at the entry or exit of the high density fluid to the high density fluid reservoir [60], as well as a pump [51] to move high density fluid through a tube of such design as to introduce high density fluid to the hydrogen flash vaporizer [10]. The high density fluid reservoir may be equipped with a fill opening which may be selectively sealed if not in use. The high density fluid reservoir [60] and the condenser [50] may be operationally coupled to the engine control unit.

Hydrogen combustion and power output of the ZED engine may be controlled by the engine control unit with input from an operator and information provided by sensors on the engine.

The engine control unit may monitor hydrogen storage availability and demand, control the rate of hydrogen combustion, control expanding fluid vapor supply to each cylinder [30], ambient temperature, cylinder temperature, piston speed, adjust to the working load on the engine, maintain a fixed rotating speed, and provide the startup ignition cycle as well as turn the engine off. The engine control unit may be connected to, and controlled by, an external computing device such as a laptop computer to optimize or vary engine performance.

In certain embodiments, engine mechanical devices (EMD) may supplement or replace the functions of the engine control unit which may not have a direct correlation in the degree of control efficiency.

In embodiments of the present invention utilizing an engine control unit, the engine control unit may be coupled to an ambient air temperature sensor, a throttle position sensor, a hydrogen flash vaporizer fuel igniter, a hydrogen fuel volume valve, a hydrogen pressure sensor, a hydrogen flash vaporizer temperature sensor, a high density fluid temperature sensor, an expanding fluid vapor temperature sensor, an expanding fluid vapor injector actuator, an engine rotating speed sensor, and/or an engine cylinder temperature sensor. These sensors may be conventional internal combustion sensors adapted to ZED engine use, or may be new sensors installed specifically with the ZED engine.

When an expanding fluid vapor condenser [50] is used with the ZED engine, the engine control unit may also incorporate a condensate temperature sensor, a cooling fan actuating sensor, and a recirculating pump actuation sensor. An electronic interface with the engine control unit may be comprised of or be operationally coupled to a thermally insulated housing, sensor multitap, a power source, modem with access hardware and software, or RJ-11 connectors which may utilize a DragonBall, StrongArm, Motorola, or any other processing chip known in the art.

According to the present invention, operational controls may be mechanically operated or used in conjunction with the engine control unit in respect to the actuation, monitoring, and operation of the ZED engine, in any combination therein without restriction or constraint in design. The expanding fluid vapor injectors may be actuated by a mechanical attachment to engines pulleys, belts, or timing wheels of the ZED engine. Engine cylinder and other temperatures may be monitored by a mechanical or electronic gauges independent of an engine control unit. The throttle may have a mechanical position locater.

The present invention may further include programming the engine control unit by a remote method using a CPU laptop, or central computer reached by modem. Alternately the ZED engine may have various pre-programmed control programs or chips for a common set of vehicles that may be loaded or inserted in a standardized engine control unit. As well alternately, a universal chip may be installed on an engine control unit which allows for selection of vehicle engine control unit standard operating or application specific operating profiles. The present invention may further include attaching a CPU to various sensors and components of the ZED engine for testing, calibration, or operation either individually or in combination.

The engine control unit may be connected to sensors and regulators in a manner to provide for engine control and safety. Sensors connected to the engine control unit may be used to determine fuel volume, fuel pressure, ambient air temperature, fuel ignition temperature, fuel combustion exhaust temperature, throttle position, crankshaft position, hydrogen flash vaporizer heating chamber temperature, hydrogen flash vaporizer heating chamber minimum and maximum fill levels, high density fluid pump activation to the hydrogen flash vaporizer, actuated vapor injector temperature sensor(s), condenser temperatures sensor(s), and actuated vapor injector pressure sensor(s). The engine control unit may control the hydrogen flash vaporizer fuel input, the high density fluid pump to introduce high density fluid to the hydrogen flash vaporizer [10], the activation of the actuated vapor injector for timing and duration of introducing the expanding fluid vapor to the cylinder(s) [30], activation of condenser cooling fan, activation of condenser high density fluid flow valves, activation of condenser high density fluid pump [51] to the high density fluid reservoir [60], and safety shut off valves in various locations. The engine control unit may be of a type and manufacture which may be operationally coupled to an external electronic device which may vary and/or set the operational functions of the engine control unit. Alternative configurations of the engine control unit may contain different components which may be of use in the disclosed apparatus, kits and methods and that any engine control unit in the art may be used within the scope of the claimed invention. In various embodiments the engine control unit may be installed in the engine or passenger compartment of the transportation vehicle. The engine control unit may have alternate operating programs installed within for selection by the operator for various common applications, or a chip containing operating programs for a particular application, or a chip which may be programmed from an external source may be in an embodiment either singularly or in combination. The engine control unit may have the provision for an external detachable electrical attachment of such design so as to externally provide a connection for the provision of receiving sensor input, control the regulators, and diagnose individual functionalities of the engine.

FIGS. 6A-6B, 7A-7B, and 8A-8B illustrate exemplary embodiments of the present invention using conventional internal combustion engines to form ZED engines. While the embodiments described below are directed to an internal combustion piston engine, the present invention is not limited thereto. Instead, the present invention includes all variants of internal combustion engines, including piston, radial, rotary, turbine and others in the art whereby a carbon based fuel is intended to be burned internally to produce mechanical power.

FIGS. 6A-6B illustrate a ZED engine according to an embodiment of the present invention. In the embodiment illustrated in FIGS. 6A-6B, internal combustion engine components retained for conversion to a ZED engine include, but are not exclusive of, the following: the engine block [1], crankshaft [8], bearings and caps to secure the crankshaft [8] to the engine block [1], connecting rod(s) [9] with cap(s) and bearings to secure the connecting rod(s) [9] to the crankshaft [8], piston(s) [31] with wrist pins, retainers and rings [32-33] to secure the piston(s) [31] to the connecting rod(s) [9] and seal the piston(s) [31] within the cylinder wall, camshaft(s) actuated either by belt, gear(s) or other attachment to the crankshaft [9], cylinder head(s) complete with rocker arms, valves, springs push rods, or electronic actuators on the internal combustion engine, as well as an intake manifold [2].

In the embodiment illustrated in FIGS. 6A-6B, hydrogen fuel is provided to a hydrogen flash vaporizer [10] through a fuel line [17]. A high density fluid may be heated through combustion of the hydrogen in the hydrogen flash vaporizer [10] to produce an expanding fluid vapor. The expanding fluid vapor may be metered directly into the intake manifold [2] which is sealed by a plate [200] of such design which may be in the location of the internal combustion engine carburetor or fuel injection throttle body so as to enable the intake manifold [2] to be pressurized by the expanding fluid vapor and direct the expanding fluid vapor to the cylinders [30]. As illustrated in FIG. 6B, the camshaft(s) may be designed so as to actuate an intake valve [3] and an exhaust valve [4] in either a two, three, or four stroke configuration for the intake of expanding fluid vapor from the intake manifold [2] to the cylinder(s) [30], and exhaust the expanding fluid vapor from the cylinders [30] to an exhaust manifold [40]. The expanding fluid vapor introduced into the cylinder [30] pushes the piston [31] housed therein to produce mechanical movement, such as turning the crankshaft [9] connected to the piston [31]. In this embodiment, the spark plug hole(s) [34] may be sealed in a manner so as to enable the cylinder [30] to be pressurized by expanding fluid vapor. The expanding fluid vapor may be exhausted through the exhaust valve [4] into the exhaust manifold [40].

The embodiment illustrated in FIGS. 6A-6B advantageously utilizes a number of internal combustion engine components, which, although may not be specifically engineered for the purpose used herein, may be readily adapted to use in the ZED engine design. For example, as illustrated in FIG. 2, enhanced or double springs [27] may replace the stock springs [26] in the valve assembly to contain the expanding fluid vapor pressure prior to the valve being actuated.

FIGS. 7A-7B illustrate a ZED engine according to another embodiment of the present invention. In the embodiment illustrated in FIGS. 7A-7B, the internal combustion engine intake manifold [2] is removed. The spark plug(s) [34] are replaced by a plurality of actuated vapor injector(s) [25 b] to introduce expanding fluid vapor into the cylinder(s) [30]. The actuated vapor injector(s) [25 b] may be controlled either electronically or mechanically. Here, the intake valve [3] may not be actuated, while the camshaft(s) may be designed or modified to only actuate the exhaust valve(s) [4] in two, three or four stroke configuration.

Alternately, gasoline, diesel or gaseous carbon fuel injector(s) may be replaced by actuated vapor injector(s) [25 a] in direct injection internal combustion engines whereby the spark or glow plug locations [34] may also be sealed (see FIG. 6B), and the introduction of expanding fluid vapor into the cylinder [30] can be operationally controlled by the actuated vapor injector(s) [25 a]. Similarly, in internal combustion engines where the fuel injectors are mounted in the intake manifold [2] or the cylinder head behind an internal combustion intake valve [3], then the internal combustion engine cylinder head may be sealed where it may normally be attached to an internal combustion intake manifold so as to enable pressurization upon the introduction of expanding fluid vapor by actuated vapor injector(s) to the engine. There, the camshaft may either actuate the intake valve(s) (3) or may not be an operating component of the engine.

In certain embodiments of the reciprocating piston variants, the actuated vapor injector(s) may introduce expanding fluid vapor through either electronic or mechanical actuation so that it may optimize the operation of the engine in regard to performance, and may be operationally coupled to the engine control unit.

For example, as illustrated in FIG. 7A, the ZED engine conversion also includes an expanding fluid vapor condenser [50]. Expanding fluid vapor in the exhaust manifold [40] is directed to the condenser [50]. The expanding fluid vapor is condensed back into high density fluid in the expanding fluid vapor condenser [50] and directed to a high density fluid reservoir [60]. A high density fluid pump [51] may be included to direct the high density fluid from the expanding fluid vapor condenser [50] to the high density fluid reservoir [60]. The high density fluid reservoir [60] supplies high density fluid to the hydrogen flash vaporizer [10].

FIGS. 8A-8B illustrate a ZED engine according to another embodiment of the present invention. In the embodiment illustrated in FIGS. 8A-8B, the internal combustion engine components retained for conversion to a ZED engine include, but are not exclusive of, the following: the engine block [1], crankshaft [8], bearings and caps to secure the crankshaft [8] to the engine block [1], connecting rod(s) [9] with cap(s) and bearings to secure the connecting rod(s) [9] to the crankshaft [8], and piston(s) [31] with wrist pins, retainers and rings [32-33] to secure the piston(s) [31] to the connecting rod(s) [9] and seal the piston(s) [31] within the cylinder wall.

In this embodiment, the internal combustion engine cylinder head(s) may be replaced by a plate [220] of such design, material and strength so as to seal the cylinder [30] in a manner that may contain pressurization by expanding fluid vapor. The expanding fluid vapor may be metered directly into the cylinder [30] from a location which may be on the cylinder plate [220] or the engine block [1]. For example, expanding fluid vapor may be provided by actuated vapor injectors [25 b] placed instead of spark plug(s) [34], or the spark plug holes [34] may be sealed, and an actuated vapor injector [25 a] may be placed on the plate [220] to introduce expanding fluid vapor into the cylinder [30]. Alternatively, expanding fluid vapor may be introduced by the actuated vapor injector [25 b] and exhausted through the actuated vapor injector [25 a]. The actuated vapor injector(s) may be actuated by electronic and/or mechanical means. The expanding fluid vapor may then be exhausted to vent the expanding fluid vapor to the atmosphere or to an expanding fluid vapor condenser [50], as illustrated in FIG. 3, or a separately actuated exhaust actuated vapor injector may be used to perform the same or similar function.

In some embodiments of the present invention, for example, as illustrated in FIGS. 8A-8B, the internal combustion engine cylinder head can be replaced with a plate of such design as to seal the top of the operating cylinder with an electronically or mechanically controlled actuated vapor injector attached thereon, whereby the internal combustion engine camshaft, push rods, rocker arms or belts are not be used.

Said plate facilitates the electronically controlled metering of expanding fluid vapor by the elimination of, by example but not exclusive of, the internal combustion engine camshaft, pushrods or camshaft belt, cylinder heads, valve rocker assemblies, rocker arm locks, intake and exhaust valves, valve springs and retainers normally present in an internal combustion engine. In this configuration, an electronically controlled actuated vapor injector may replace the internal combustion engine type intake design. This configuration may require a more sophisticated electronic control, as opposed to a mechanical control of the engine. As well, this embodiment may also reduce a weight and size of the ZED engine where such considerations are required in the end-use application.

The expanding fluid vapor introduced into the cylinder [30] can be exhausted through the cylinder exhaust outlet into the exhaust manifold [40], or may be vented in reverse through the expanding fluid vapor introduction mechanism, or through a secondary component.

In other embodiments of the present invention, the internal combustion engine block may be modified with an opening through the cylinder wall above the lowest point of travel of the top of the piston [31] so as to vent the expanding fluid vapor irrespective of the expanding fluid vapor intake to the cylinder.

The expanding fluid vapor may be recovered as condensate and reheated for a closed loop operation, or vented externally.

As illustrated in FIG. 9, an actuated vapor injector may comprise an electrically actuated magnet [21] to actuate a plunger [22]. The plunger [22] may normally be in a closed position to block supply of expanding fluid vapor. When triggered, an electrical power source [23] can power the electrically actuated magnet [21] to attract the plunger [22] and open supply of expanding fluid vapor. While a magnetically actuated vapor injector is illustrated in FIG. 9, the present invention is not limited thereto, and other actuating mechanisms can be use to selectively provide expanding fluid vapor supply. For example, another embodiment of the actuated vapor injector noted in FIG. 9 may open and close the valve by mechanical means.

Said actuated vapor injector may be of such design as to operate in a normally closed position and by actuation be opened to allow the passage of expanding fluid vapor through the body of the actuated vapor injector. The duration and timing of said opening duration may be of such a nature as to cause movement of the piston(s) [31] within the cylinder(s) [30] and thereby mechanical motion. The location of the actuated vapor injector(s) in relationship to the cylinder [30] may be in any location and attached to any component which allows its functionality in respect to the expanding fluid vapor and the cylinder [30]. Said actuated vapor injector may be of such design so as allow the expanding fluid vapor to reverse its flow through the actuated vapor injector(s) in an exhaust cycle and thereafter be vented to the atmosphere or directed toward the condenser [50]. In other embodiments of the present invention, the introduction of the expanding fluid vapor into the cylinder [30] may be termed the power stroke of the engine. The expulsion of the expanding fluid vapor from the cylinder may be termed the exhaust stroke of the engine. There is no constraint in the design of the engine to require the exhaust stroke to follow a power stroke, nor a constraint whereby strokes must alternate successively, or that all cylinders [30] in a multi-cylinder application must be in use during the operation of the engine at all speeds. In some embodiments of the invention, the timing and volume of expanding fluid vapor through the actuated vapor injector may cause the engine to decelerate, as opposed to accelerate, the rotational speed of the engine, or the actuated vapor injector(s) may be activated in such a manner as to reverse the rotational direction of the engine. The actuated vapor injector(s) may be operationally coupled to the engine control unit to control an operation thereof.

The expanding fluid vapor may be exhausted from the cylinder [30] and vented to the atmosphere, or may be collected in a condenser [50] and returned to a high density fluid reservoir (EFR) [60]. In embodiments where the expanding fluid vapor is vented to the atmosphere, the ZED engine may also include a high density fluid tank to store a source of high density fluid. In embodiments where a condenser [50] is used, the expanding fluid vapor is expelled from the cylinder [30] in the exhaust stroke and a tube of such volume, shape, design, insulation, material and connection is used so as to move the expanding fluid vapor to the condenser [50]. Said tube can include the exhaust manifold [40] of the internal combustion engine, as illustrated in FIG. 3. Said condenser [50] may be in a location whereby it is exposed to ambient atmospheric temperature in such a manner as to cool the expanding fluid vapor in order for the expanding fluid vapor to return to a liquid state. The condenser [50] may be equipped with sensors to monitor atmospheric, expanding fluid vapor, and high density fluid temperatures. A cooling fan (not illustrated) may be connected to the condenser [50] to increase a cooling rate of the expanding fluid vapor to high density fluid, whereby said fan activation may be operationally controlled by the engine control unit or independently by a temperature sensor. Said condenser [50] may be connected to an electrical or mechanical high density fluid pump [51] to move the condensate by tube(s) of such volume, shape, design, insulation, material and connection to the high density fluid reservoir [60].

In addition to the embodiments described above to form a ZED engine using a conventional internal combustion engine base, additional modifications can be made to a conventional internal combustion engine design to maximize efficiency and functionality of the ZED engine.

A disadvantage of conventional engines converting vapor expansion force into mechanical work is that as soon as the vapor starts to condense, the vapor contracts in volume and ceases to be converted into mechanical work. Accordingly, maintaining the vapor above the condensation temperature increases the efficiency by which the vapor expansion force of the expanding fluid vapor is converted into mechanical work. Embodiments of the present invention utilize a novel approach of heat shrouding the power cylinders so as to scavenge as much heat as possible from the hydrogen combustion event. That is, as illustrated in FIGS. 2-3, exhaust heat produced by the combustion of hydrogen in the hydrogen flash vaporizer is recovered and re-routed to the engine block [1] to heat the power cylinders [30]. Accordingly, it is possible to scavenge heat available from the hydrogen combustion to heat the expanding fluid vapor in the cylinders [30] to maintain the expanding fluid vapor as high above the temperature point of condensation as possible. The ZED engine maximizes the utility of the heat of combustion by shrouding the cylinders [30] with combustion exhaust heat which would normally be vented to the atmosphere, where it is otherwise wasted and effectively decreases the efficiency of a conventional engine. The ZED engine according to the present invention uniquely shrouds the cylinders [30] by using coolant passages [300] cast into the internal combustion engine block to carry the hydrogen combustion exhaust heat. Heat shrouding using the excess heat of combustion cannot be done with carbon-base fuels because of the radiant heat emitted by those fuels during combustion. If the excess heat from a carbon-fuel combustion was re-routed, the radiant heat would localize itself and could severely damage the engine block [1]. In contrast, because hydrogen combustion produces little radiant heat, the exhaust heat can travel throughout the block to deliver uniform heating. Because the coolant passages [300] are optimally placed to remove heat from the cylinders in a conventional internal combustion engine, they are also optimally placed to heat the cylinders [30] in a ZED engine. By routing the exhaust heat of the hydrogen flash vaporizer [10] through the engine block [1], the expanding fluid vapor is kept hot and expanding so as to maximize a mechanical work produced.

In addition, the engine block [1] can be further modified to provide additional shrouding of the cylinders [30] to further increase a thermal shrouding of the ZED engine. For example, the cylinders [30] may be fitted with a cylinder sleeve having additional passages defined therein to more closely shroud the cylinders [30] with the vaporizer exhaust. FIG. 12 illustrates a shrouding cylinder sleeve according to an embodiment of the present invention. As illustrated in FIG. 12, the engine cylinders [30] may be bored out so as to be fitted with a shrouding cylinder sleeve [500], similar to those normally used in the trade to repair a damaged cylinder. The shrouding cylinder sleeve [500] defines one or more passages [510] to channel the vaporizer exhaust around the cylinder [30] when fitted in the cylinder bore. That is, prior to fitment with the shrouding cylinder sleeve [500], the engine cylinder [30] bore may be engraved with recesses and connected to the coolant passages [300] such that when the sleeve is installed, the shrouding cylinder sleeve [500] covers the engraved recesses to define passages to facilitate the passage of exhaust heat immediately adjacent to the cylinder for optimal heat energy recovery. Moreover, a contact surface of the pistons [31] may be coated with a ceramic layer [301] to protect the piston [31] from any corrosive or damaging effects of the expanding fluid vapor as well as to minimize an absorption of heat by the piston [31], which would decrease the temperature of the expanding fluid vapor, and lower engine efficiency.

In embodiments of the invention using a hydride tank as the hydrogen fuel tank [10], the thermal efficiency of the ZED engine can also be improved by further utilizing the residual heat of the hydrogen combustion. For example, the residual heat can be directed to the hydride tank to release the hydrogen. As described above, in one exemplary embodiment of the present invention, the exhaust heat of the hydrogen combustion in the hydrogen flash vaporizer can be re-routed through the cooling passages [300] of a conventional internal combustion engine to heat the engine block [1] and maintain a temperature of the expanding fluid vapor. After heating the engine block [1], the exhaust heat can be further re-routed to the hydride tank [10] to heat the hydride and help release hydrogen to be used as fuel. As described above, ZED engines can have a high-grade exhaust at 100-125° C. which can be routed through a hydride tank [100] to release hydrogen for fuel and combustion.

In other embodiments of the invention, the ZED engine also has the capability to “twin” piston cylinders to effectively double the mechanical power stroke of the engine. For example, as illustrated in FIG. 10, twining of two cylinders [30] can be produced by introducing the expanding fluid vapor into a first cylinder [30 a], which pushes a first piston [31 a] downward. In the last 20% or so of the first piston's [31 a] travel, cylinder [30 a] is slotted to a self contained coolant passage [300] so that the expanding vapor can now escape cylinder [30 a] and travel up the coolant passage [300] to a top of a second cylinder [30 b], which is slotted at the top. Arranging twin cylinders [30 a and 30 b] in this communicative manner allows the continued expansion of the expanding fluid vapor to also push a second piston [31 b], and thus, double the mechanical work produced (efficiency) by the expanding fluid vapor before it is vented to the condenser [50] or the atmosphere.

The embodiments of the present invention described above illustrate a highly efficient hydrogen fueled zero or low emission engine. The present invention can be used to build a ZED engine from scratch or can be used to adapt conventional internal combustion engine design and components to fabricate a ZED engine.

The conversion of an internal combustion engine design to external combustion is significantly augmented by the efficient heat energy transference using the high density binary working fluid (HDF) and the innovative recuperative heat exchange processes described above. The ZED engine can be considered an example of a “bottoming cycle” engine which extracts additional power from the exhaust heat of the hydrogen combustion, which is uniquely suited to this design due to its ignition characteristics and the absence of significant radiant heat transfer.

Using a binary fluid high density fluid allows the ZED engine to have a smaller displacement volume and a higher efficiency potential than any known external (or internal) combustion engines, allowing the ZED engine to mirror the efficiency of a Kalina cycle engine, but without the constraints of a Kalina cycle engine. A ZED engine is compact, utilizing existing internal combustion engine internal heat transfer design in reverse to its original design intention, thereby requiring a fraction of the volume of a corresponding Kalina cycle design, while increasing an efficiency of converting the expanding fluid vapor pressure to mechanical work.

As described above, the ZED engine uniquely exploits the ignition temperature and stoichiometric perfection of hydrogen external combustion under all application loads to recycle heat that would otherwise be wasted through discharge or removal. Because the original internal combustion engine coolant passages [300] are not needed for internal combustion engine cooling when converted to a ZED engine design, they can be modified and utilized to conduct and direct otherwise wasted heat from the hydrogen combustion exhaust to the power cylinders defined herein as a Berk cycle engine heat scavenging method. The extended application of hydrogen combustion heat, due to the unique increased recuperative capacity of the engine, thereby extends the expansion event of the binary high density fluid throughout its full expansion temperature range, creating a Kalina-effect heat scavenging and shrouding of the cylinders to retain heat and optimize vapor expansion conversion to mechanical power.

The ZED engine may render obsolete the internal combustion engine starter, air filter, ignition system, fuel delivery system, coolant system, exhaust and anti-pollution devices, while delivering performance in the range of 2-3 horsepower per cubic inch of engine displacement.

The hydrogen flash vaporizer transfers heat from the hydrogen combustion event to the high density fluid which is first converted from liquid by atomization, and is then vaporized in the hydrogen flash vaporizer, and the engine extracts mechanical power from the resultant metered expansion of the fluid at a calculated rate of about 2000-2500:1 expansion ratio.

By shrouding the cylinders with scavenged heat to maximize vapor expansion using the Berk cycle, and then using the residual heat to release hydrogen as a fuel, the ZED engine can produce 2-3 horsepower per cubic inch of displacement whereas other internal combustion hydrogen engines and fuel cell engines produce approximately one-quarter the power using the same amount of hydrogen fuel.

FIG. 13 of the drawings is a diagram illustrating the interconnection of the engine control unit to the various sensors that provide input to the control unit and actuators, valves and the like whose operation are controlled by the engine control unit. The present diagram is a representation and those skilled in the art will be able to make modifications and enhancements thereto. Engine control unit [600] is a microprocessor controlled unit that is in electrical communication with the various sensors and actuators that dictate or influence engine operation. For example, throttle input is received by sensor [601], typically by the user's pressing on the accelerator pedal. Sensors that control the engine performance include hydrogen flash vaporizer temperature sensor [15A] and hydrogen flash vaporizer pressure sensor [15B] that determine the volume of high density fluid in the hydrogen flash vaporizer and monitor the volume of expanding fluid vapor provided to the actuated vapor injector(s) [25]. Also illustrated are engine block temperature sensor [37], engine speed/crankshaft position sensor [8A], condenser fan sensor [602] and thermal switch [603], and carbon fuel sensor [604]. Actuators, valves and the like are shown including hydrogen flash vaporizer regulator [15], hydrogen flash vaporizer igniter [16], fuel flow volume regulator [18], fuel shut off [19], air bleed valve actuator [36], bypass valve [401] and actuated vapor injectors [25] shown in two banks. These sensors and actuators may be conventional internal combustion sensors adapted to ZED engine use, or may be new sensors installed specifically with the ZED engine.

All of the methods, kits, apparatus, devices, and components disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. Although a few embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents. 

1. A method of converting a conventional internal combustion engine to a hydrogen fuel external combustion engine, comprising: installing a high density fluid reservoir to store a high density fluid; installing a hydrogen fuel tank to store a hydrogen fuel; installing a hydrogen flash vaporizer to combust the hydrogen fuel received from the hydrogen fuel tank and vaporize the high density fluid received from the high density fluid reservoir into an expanding fluid vapor; modifying the conventional internal combustion engine to receive the expanding fluid vapor and to convert an expansion force of the expanding fluid vapor into mechanical motion: and modifying coolant passages defined in the conventional internal combustion engine to receive at least a portion of heat produced by the hydrogen combustion in the hydrogen flash vaporizer to shroud the conventional internal combustion engine and heat the expanding fluid vapor therein.
 2. The method of claim 1, further comprising: directing the heat of the hydrogen combustion from the cooling passages to the hydrogen tank to heat a hydride store therein to release the hydrogen fuel.
 3. The method of claim 1, further comprising: modifying at least one of the coolant passages and other passages formed in the conventional internal combustion engine to receive the heat produced by the hydrogen combustion to shroud the conventional internal combustion engine.
 4. The method of claim 3, wherein the engine comprises at least one piston within a cylinder, and the method further comprises: engraving the cylinder with at least one groove connected to the coolant passages; and fitting a shrouding sleeve in the cylinder to define other passages in the cylinder to shroud the piston with the heat of the hydrogen combustion.
 5. The method of claim 1, wherein the high density fluid comprises a binary mixture of water and ammonia.
 6. The method of claim 1, wherein the hydrogen fuel tank comprises a hydride tank, and the method further comprises: directing heat produced by the hydrogen combustion to the hydrogen tank to release the hydrogen fuel.
 7. An external combustion engine system, comprising: a tank to store a source of fuel; a vaporizer to combust the fuel and vaporize an atomized liquid introduced into the vaporizer to an expanding fluid vapor; an internal combustion engine to receive the expanding fluid vapor and convert an expansion force thereof into mechanical force; and a vaporizer exhaust system to direct at least a portion of the heat produced by the combustion of the fuel into passages defined in the internal combustion engine to shroud the internal combustion engine and heat the expanding fluid vapor therein, wherein the atomized liquid, being a mixture of water and ammonia, comprises at least 50% water.
 8. An external combustion engine, comprising: a hydrogen tank to store a source of hydrogen fuel; a hydrogen flash vaporizer to combust the hydrogen fuel and vaporize an atomized liquid introduced into the hydrogen flash vaporizer to an expanding fluid vapor; an engine to receive the expanding fluid vapor and convert an expansion force thereof into mechanical force; and a hydrogen flash vaporizer exhaust system to direct at least a portion of heat produced by the combustion of the hydrogen fuel to the engine to heat the expanding fluid vapor in the engine, wherein the engine is a conventional internal combustion engine and the hydrogen flash vaporizer exhaust system directs the heat of the hydrogen fuel combustion to at least one of original coolant passages defined in the conventional internal combustion engine and other passages within a conventional internal combustion engine block to shroud the conventional internal combustion engine with the heat of the hydrogen fuel combustion.
 9. The external combustion engine of claim 8, further comprising a plurality of actuated vapor devices to regulate the introduction of the expanding fluid vapor into the conventional internal combustion engine.
 10. The external combustion engine of claim 8, further comprising an information processing and control system.
 11. The external combustion engine of claim 10, wherein the information processing and control system regulates the flow of hydrogen to the hydrogen flash vaporizer, and the flow of expanding fluid vapor to the conventional internal combustion engine.
 12. The external combustion engine of claim 8, wherein the conventional internal combustion engine comprises at least one piston within a cylinder, the cylinder incorporating at least one groove connected to the original coolant passages, and wherein the cylinder is fitted with a shrouding sleeve to define other passages for the heat of the hydrogen fuel combustion to shroud the piston.
 13. The external combustion engine of claim 8, wherein the hydrogen tank comprises a hydride tank and wherein at least a portion of the heat of the hydrogen fuel combustion is directed from the conventional internal combustion engine to the hydride tank to release the hydrogen fuel.
 14. The external combustion engine of claim 13, wherein the hydrogen tank comprises a hydride tank and wherein at least a portion of the heat of the hydrogen fuel combustion is directed from the coolant passages defined in the conventional internal combustion engine to the hydride tank to release the hydrogen fuel.
 15. The external combustion engine of claim 7, wherein the hydrogen flash vaporizer comprises: a hydrogen flash vaporizer body defining a heating chamber, a combustion chamber, and an exhaust; a plurality of heating tubes disposed within the heating chamber to connect the combustion chamber to the exhaust; and a hydrogen burner, disposed in the combustion chamber to combust the hydrogen fuel and heat an inside surface of the heating tubes, wherein an air intake is provided in the combustion chamber to combine the hydrogen fuel with air during combustion thereof, and wherein the heated air travels through the heating tubes to the exhaust.
 16. The external combustion engine of claim 7, wherein the atomized liquid comprises a high density fluid.
 17. The external combustion engine of claim 16, wherein the high density fluid comprises a binary mixture of two fluids selected to have cooperative molecular weights so as to widen the temperature range at which the binary fluid converts to a vapor.
 18. The external combustion engine of claim 16, wherein the high density fluid comprises a binary mixture of water and ammonia.
 19. The external combustion engine of claim 17, wherein the high density fluid comprises 5-50% ammonia and 50-95% water.
 20. The external combustion engine of claim 16, wherein the high density fluid comprises 15-50% ammonia and 50-85% water.
 21. An external combustion engine, comprising: a high density fluid reservoir to store a high density fluid; a hydrogen fuel tank to store hydrogen fuel; a hydrogen flash vaporizer to combust the hydrogen fuel received from the hydrogen fuel tank and vaporize the high density fluid received from the high density fluid reservoir into an expanding fluid vapor; a piston engine to receive the expanding fluid vapor and convert an expansion force thereof into mechanical force; and an exhaust to direct heat produced by the hydrogen combustion in the hydrogen flash vaporizer to the piston engine to heat the expanding fluid vapor in the engine, wherein the piston engine is a conventional internal combustion piston engine, and wherein the heat of the hydrogen combustion is directed to at least one of original coolant passages and other passages defined in the conventional internal combustion piston engine to shroud at least one of pistons and cylinders defined in the conventional internal combustion piston engine with the heat of the hydrogen combustion.
 22. The external combustion engine of claim 21, wherein the hydrogen tank comprises a hydride tank, and wherein heat is directed from the piston engine to the hydride tank to release the hydrogen fuel. 